Safe Torque Off (Sto) Safety Function; Function Description; Advanced Commissioning - Siemens SINAMICS G110M Operating Instructions Manual

Advanced commissioning

6.8 Safe Torque Off (STO) safety function

6.8 Safe Torque Off (STO) safety function
These operating instructions describe the commissioning of the STO safety function when it
is controlled via a fail-safe digital input.
You can find a detailed description of all safety functions and their control using PROFIsafe
in the "Safety Integrated" function manual.
6.8.1

Function description

What does the STO safety function do?
An inverter with active STO function prevents energy supply to the motor. The motor can no
longer generate torque at the motor shaft.
Consequently, the STO function prevents the starting of an electrically-driven machine
component.
Table 6- 41
1. The inverter recognizes the selection of STO
2. The inverter interrupts the energy supply to the
3. The inverter signals that "STO is active" via a
Figure 6-52
If the motor is still rotating (B) when STO is selected, then it coasts down to standstill.
The STO safety function is standardized
The STO function is defined in IEC/EN 61800-5-2:
238
Manuals and technical support (Page 335)
The principle of operation of STO
Safe Torque Off (STO)
via a safety-relevant input or via the PROFIsafe
safe communication.
motor.
safety-relevant output or via the PROFIsafe
safe communication.
Functionality of STO when the motor is at standstill (A) and rotating (B)
Standard inverter functions linked with STO
---
If you use a motor holding brake, the inverter
closes the brake.
---
Distributed converter for SIMOGEAR geared motors
Operating Instructions, 06/2016, FW V4.7.6, A5E31298649B AG